Test strip fixing device for optical measurement of analytes

Abstract

The present invention provides a test strip fixture, comprising: a mobile device having a camera configured for use in a method for determining a concentration of an analyte in a bodily fluid by using the mobile device having a camera, the method comprising capturing at least one image with the camera including at least a portion of an optical test strip and at least a portion of the test strip retaining device, the optical test strip having a sample of the bodily fluid applied onto a reagent test area of ​​the optical test strip, the image including at least a portion of the reagent test area onto which the sample of the bodily fluid has been applied, and the image including at least a portion of a top surface of the test strip retaining device; a) an essentially planar shape; b) a cutout portion; c) a top surface including a plurality of color reference fields with known reference color values, including gray reference fields locally arranged around the cutout and around at least a portion of the non-gray color reference fields, and including position detection code elements; d) a lower surface comprising a fastening element for detachable connection of an optical test strip to said test strip fastening device such that a reagent testing area can be aligned with the notch; The present invention relates to a test strip fixing device comprising:

Description

Technical Field

[0001] The present invention relates to a test strip fixing device having, on an upper surface, a color reference field of known reference color values including a gray reference field and a position detection code element, and being adapted to removably connect an optical test strip to the test strip fixing device. The test strip fixing device is configured to be used in a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera. Further, the present invention relates to a kit comprising the test strip fixing device and an optical test strip used together with the test strip fixing device in such a method. The test strip fixing device and the method can be particularly used for medical diagnosis in order to qualitatively or quantitatively detect one or more analytes in a body fluid, such as for detecting glucose in blood or interstitial fluid.

Background Art

[0002] In the field of medical diagnosis, it is often necessary to detect one or more analytes from a sample of a body fluid such as blood, interstitial fluid, urine, saliva, or other types of body fluids. Examples of analytes to be detected are glucose, triglycerides, lactate, cholesterol, or other types of analytes normally present in such body fluids. Depending on the concentration and / or presence of the analyte, appropriate treatment can be selected as needed.

[0003] Generally, apparatus and methods known to those skilled in the art utilize a test element containing one or more test chemicals, which can perform one or more detectable detection reactions, such as optically detectable detection reactions, in the presence of the analyte to be detected. For reference to the test chemicals contained in the test element, see, for example, J. Hoenes et al.: The Technology Behind Glucose Meters: Test Strips, Diabetes Technology & Therapeutics, Volume 10, Supplement 1, 2008, S-10 to S-26.

[0004] In analytical measurements, particularly those based on color reactions, one technical challenge lies in evaluating the color change resulting from the detection reaction. In addition to using dedicated analytical instruments such as handheld blood glucose meters, the use of commonly available electronic devices such as smartphones and portable computers or other mobile devices has become increasingly prevalent in recent years.

[0005] In contrast to laboratory measurements and measurements performed using dedicated analytical measuring instruments, when using mobile computing devices such as smartphones, it is necessary to consider various additional influences, such as lighting conditions and positioning methods, particularly the positioning of the mobile device relative to optical test strips and / or any auxiliary means such as color reference charts. It can be difficult to adequately consider such additional influences. Nevertheless, in order to ensure or improve the reliability of analyte detection results in these cases, it is beneficial to adequately address any such aspects that may be expected to affect the desired analyte detection or measurement.

[0006] In particular, in methods for determining the concentration of an analyte in a bodily fluid by using a mobile device with a camera, if auxiliary means such as a color reference chart are used in conjunction with an optical test strip, the camera must be aligned with or positioned relative to both the optical test strip and the color reference chart. To facilitate this effort, the reference color may be used directly on a support that also contains the test chemical. However, if the color reference chart is used separately from the optical test strip, the positioning of the optical test strip on the one hand and the color reference chart on the other hand must conform to the requirements of the measurement method, which usually includes the positioning of the test strip and the reference chart relative to the camera and to each other. The latter aspect, namely the positioning of the test strip and the reference chart relative to each other, is all the more relevant if the measurement method includes not only reading color information from the test chemical from a reagent test field on the optical test strip, but also reading other information from the optical test strip, such as additional color information, calibration information, or lot-specific information. Such additional information may be provided, for example, on the carrier or support of the optical test strip.

[0007] Therefore, camera-based evaluation of optical test strips typically requires the detection of the test strip and its reagent test field, and, if a color reference chart with a color reference field is used, the chart and the position of the color reference field on it must also be detected. For this purpose, it is even more important to ensure the high quality of images captured by a camera, such as the camera of a mobile device, so that such images can be processed in methods of analyte measurement performed using a mobile device. However, in this regard, the necessary computing power must be considered. High-quality images include one or more of the following embodiments: - The images must be clear (for example, the color reference chart and optical test strips must be in the focal plane). - The exposure is appropriate. - Good pixel resolution (at least Full HD, i.e., 1920 x 1080 pixels; in some cases, HD, i.e., 1280 x 720 pixels, may be sufficient). - A good dynamic range, such as actual 8-bit resolution, should be available. - Compression should not be used, or only non-significant compression should be used (e.g., color, spatial). - In the case of a color reference chart, it is essential to know or determine the relative position between the test field of the test strip and the relevant color reference field on the chart (such as a colored or gray field) in the image captured by the camera of the mobile device. - In a color criterion chart, for each color criterion field, it may be necessary to derive specific statistics (such as the average color value) and / or histograms to ensure that function checks work properly and / or that the analytes can be calculated accurately. - In the case of a color reference chart, the interrelationships between the test and / or color reference fields can be derived to calculate or guarantee the accuracy of the analyte concentration.

[0008] Current systems, which involve the use of colored reference charts, often allow users to place test strips on the reference chart, in principle, anywhere on the chart. Therefore, in such scenarios, it is necessary to safely detect the test strips and, if necessary, notify the user to better align the test strips with the color reference chart.

[0009] In the case of high-end smartphones, checking all necessary elements (test strips, reagent test fields, color reference fields, etc.) as well as the image quality of each recorded frame, is usually possible multiple times per second, for example, providing about 20 frames per second. However, in the case of widely used low-end to mid-range smartphones, only a few frames per second, or even a single frame, can be processed in this manner. Therefore, it is important to minimize the pixel-based calculations performed by the mobile device (e.g., finding the test strips and / or reagent test fields) as much as possible.

[0010] European Patent Application Publication No. 3018470 describes a method for a terminal that measures biometric information, comprising: receiving an image of a biosensor including a reagent pad from which a sample is collected; and determining the value of the reagent reaction between the reagent pad and the sample by comparing the brightness information of the reaction area of ​​the reagent pad in the received image with reference brightness information in the received image. The biosensor may also include reference brightness information and identification information in addition to the reagent pad.

[0011] European Patent Application Publication No. 3143378 relates to a method comprising: capturing images of a dipstick having a colored test reagent and a calibration array having a plurality of colored reference elements; deriving local illumination parameters related to the dipstick and the calibration array based on the captured images; determining whether the illumination parameters fall within a predetermined set of illumination boundary conditions; applying one or more image enhancement operations to the captured images based on a predefined mapping between the derived illumination parameters and one or more required adjustments to generate an enhanced image; and interpreting the colored test reagent based on the colored reference elements in the enhanced image.

[0012] International Publication No. 2019113812 describes a method for quantitatively detecting the concentration of a solution based on color recognition, which in particular includes the following main steps: step S4, identifying information corresponding to the color reaction region and each color block by image recognition technology and converting diffuse reflected light information into color coordinates in a specific color space; step S5, obtaining equivalent ambient light by performing equivalent calculations for the color reaction region, color block diffuse reflected information, ambient light, and other external factors by optical principles; step S7, calculating a standard color for the color reaction region; and step S8, calculating the concentration of the solution to be detected using the correspondence between the standard color for the color reaction region and the concentration of the solution to be detected. A card slot may be used to position the color reaction region, the card slot is positioned in the center of the observation area, and the color blocks are distributed in a matrix on both sides of the card slot, with the color blocks and card slot being symmetrically distributed in the center of the observation area.

[0013] U.S. Patent Application Publication No. 20180146175 relates to a system for determining the true color of an unknown color sample, comprising: a template including a notch and a plurality of concentric rings around the notch, each of which has an offset grayscale modulated as a function of polar coordinate angles, and triangular relationships between the grayscales of the plurality of concentric rings; an RGB color module configured to determine a first radial cross section of one of the concentric circles having an intensity that matches a determined average red value of an image of the unknown color sample in an image of the template over the unknown color sample, and to determine the true average red value of the unknown color sample based on the intensity profile of one of the concentric circles and the polar angle of the first radial cross section; and an angle module configured to determine the polar angle of the first radial cross section.

[0014] Despite the advantages associated with using mobile computing devices for the purpose of performing analytical measurements, one of the remaining technical challenges is to ensure or enhance the reliability of test results for analyte measurements involving such mobile computing devices and test elements such as optical test strips, taking into account any aspects that may be expected to affect the detection or measurement of the desired analyte, such as ambient lighting conditions and the relative orientation of optical test strips or color reference charts. Issues to be resolved

[0015] Therefore, it is desirable to provide apparatus and methods that address the aforementioned challenges at least partially. Specifically, it is desirable to provide apparatus and methods that enable reliable, mobile-based determination of analyte concentrations in body fluids and minimize the influence of external factors such as ambient lighting conditions and the relative position of the mobile computing device and the optical test strip on analyte detection or measurement. In particular, the apparatus and methods provided should be adapted to include the appropriate use of reference colors provided separately from the optical test strip. Furthermore, all necessary elements, such as color reference fields on a color reference chart, should be identified in a digital image with low computational cost. [Overview of the project]

[0016] This problem is addressed by a test strip fixation device configured for use in a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, and further by a kit including a test strip fixation device and an optical test strip, and by a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, an optical test strip, and a test strip fixation device, in either case having the features of an independent claim. Advantageous embodiments that can be realized in a single manner or in any arbitrary combination are described in the dependent claims.

[0017] Where used below, the terms “have,” “equip,” or “include,” or any grammatical variations thereof, are used inclusively. Therefore, these terms may refer to both situations in which the entity described in this context has no further features beyond those introduced by these terms, and situations in which one or more additional features exist. For example, the expressions “A has B,” “A equips B,” and “A includes B” may both refer to situations in which A has no other elements besides B (i.e., A consists solely of B and exclusively of B), and situations in which entity A has one or more additional elements besides B, such as element C, elements C and D, or even further elements.

[0018] Furthermore, it should be noted that the terms “at least one,” “one or more,” or similar expressions indicating that a feature or element can exist one or more times are usually used only once when introducing each feature or element. In most cases below, when referring to each feature or element, the expressions “at least one” or “one or more” will not be repeated, despite the fact that each feature or element can exist one or more times.

[0019] Furthermore, where used below, the terms “preferably,” “more preferably,” “particularly,” “more especially,” “specifically,” “more specifically,” or similar terms are used in conjunction with any feature without limiting the possibility of alternatives. Thus, any features introduced by these terms are arbitrary and are not intended to restrict the scope of the claims in any way. The present invention may be carried out by using alternative features, as those skilled in the art will recognize. Similarly, any features introduced by “in embodiments of the present invention” or similar expressions are intended to be arbitrary features without limitations on alternative embodiments of the invention, without limitations on the scope of the invention, and without limitations on the possibility of combining such introduced features with other arbitrary or non-arbitrary features of the invention.

[0020] In a first aspect of the present invention, a test strip fixing device is disclosed. The structural elements of the test strip fixing device are described in further detail below herein.

[0021] It should be noted that the test strip fixing device according to the present invention is configured for use in a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, and further uses an optical test strip. Therefore, the requirement for such optical detection or measurement of the analyte, some of which is discussed in the context of the background art described herein, determines, at least to some extent, the design and arrangement of at least some of the structural elements of the test strip fixing device. Thus, since a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, and further using an optical test strip, represents another aspect of the present invention, it is appropriate to first describe some general aspects of the method before describing the details of the test strip fixing device itself. This will allow for a better understanding of how the test strip fixing device can be used in a method for determining the concentration of an analyte in relation to an optical test strip.

[0022] A method for determining the concentration of an analyte in a body fluid as described herein includes the use of a mobile device having a camera and a processor. Furthermore, an optical test strip is used, comprising a carrier and a reagent test area positioned on the carrier, wherein the carrier includes a transparent zone or a notched zone at the location of the reagent test area. The optical test strip is detachably connected to a test strip holder. A sample of the body fluid is applied to the reagent test area, thereby forming a color that can be observed from above through the notch of the test strip holder and through the transparent zone or notched zone of the carrier of the optical test strip. The method includes capturing at least one image by the camera, including at least a portion of the optical test strip and at least a portion of the top surface of the test strip holder. The image further includes at least a portion of the reagent test area to which the body fluid sample is applied, and further includes at least a portion of a color reference field. The method further includes determining the concentration of the analyte from the color formed within the reagent test area, taking the color reference field into consideration, using a processor.

[0023] The term “determining the concentration of an analyte in a body fluid,” also known as “analytical measurement,” as used herein, is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to the quantitative and / or qualitative determination of at least one analyte in an aliquot of any sample or body fluid, but is not limited to this. For example, body fluid can include one or more of blood, interstitial fluid, urine, saliva, or other types of body fluids, particularly blood. The result of the concentration determination may, for example, be the concentration of an analyte and / or the presence or absence of the determined analyte. Specifically, for example, the analytical measurement may be a blood glucose measurement, and therefore the result of the analytical measurement may, for example, be a blood glucose concentration. In particular, the analytical measurement result value may be determined by the analytical measurement.

[0024] Thus, the term "analyte concentration value", which is often also referred to as the "analytical measurement result value" as used herein, is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. Specifically, without limitation, this term can refer to a numerical representation of the analyte concentration in a sample.

[0025] Without narrowing the scope, the present invention can be specifically described with respect to blood glucose measurement. However, it should be noted that the present invention can also be used for other types of analytical measurements using test elements. By way of example, at least one analyte can be or can include one or more specific chemical compounds and / or other parameters. By way of example, one or more analytes involved in metabolism, such as blood glucose, can be determined; additionally or alternatively, other types of analytes or parameters, such as, for example, pH values, can be determined.

[0026] The method outlined above includes using at least one mobile device having at least one camera. The term "mobile device" as used herein is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. Specifically, without limitation, this term can refer to a portable electronic device, more specifically, a portable communication device such as a mobile phone or a smartphone. Additionally or alternatively, the portable device can also refer to a tablet computer or another type of portable computer having at least one camera and at least one processor. Furthermore, additionally or alternatively, the mobile device can also refer to a computer such as a laptop computer or a PC equipped with an internal or external camera such as an external web camera.

[0027] As used herein, the term "camera" is a broad term and should be given its ordinary and customary meaning to those skilled in the art and should not be limited to a special or customized meaning. Specifically, but not limited to, this term can refer to a device having at least one imaging element configured to record or image spatially resolved one-dimensional, two-dimensional, or three-dimensional optical data or information. By way of example, a camera can include at least one camera chip such as at least one CCD chip and / or at least one CMOS chip configured to record an image. As used herein, specifically but not limited to, the term "image" can specifically relate to data recorded by using a camera, such as a plurality of electronic readings from an imaging element such as pixels of a camera chip.

[0028] In addition to at least one camera chip or imaging chip, a camera can include one or more additional elements, such as one or more optical elements, for example, one or more lenses. By way of example, a camera can be a fixed-focus camera having at least one lens that is fixedly adjusted with respect to the camera. However, alternatively, a camera can also include one or more variable lenses that can be adjusted automatically or manually. The present invention should in particular be applicable to cameras that are commonly used in mobile applications such as notebook computers, tablets, or specifically mobile phones such as smartphones. Thus, specifically, a camera can be part of a mobile device that includes one or more data processing devices, such as one or more data processors, in addition to at least one camera. However, other cameras can also be used.

[0029] The test strip fixing device is configured for use in conjunction with an optical test strip, particularly in the methods described herein. Thus, as used herein, at least one optical test strip having at least one reagent test area, also referred to as the “test area.” The term “optical test strip” as used herein is a broad term, and its usual customary meaning should be given to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to any element or apparatus configured to perform a color change detection reaction, but is not limited to this. An optical test strip may also be called a test strip or test element, and all three terms can refer to the same element. An optical test strip may, in particular, have a reagent test area containing at least one test chemical for detecting at least one analyte. As an example, an optical test strip may comprise at least one substrate, such as at least one carrier, to which at least one reagent test area is applied or incorporated. In particular, an optical test strip may further include one or more reference areas, such as a white field and / or a black field. Additionally or alternatively, the substrate or carrier itself may be, or contain, such reference areas. For example, at least one carrier can be in the form of a strip, thereby making the test elements into a test strip. These test strips are generally widely used and available. A single test strip can carry a single test field, or multiple test fields having the same or different test reagents contained within it.

[0030] Furthermore, as used herein, the term “reagent test area” (also referred to herein as “test field”) is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term may refer to an aggregated amount of a test chemical, such as a circular, polygonal, or rectangular field having one or more layers of material having at least one layer of the test field containing the test chemical. For reference to test chemicals contained in optical test strips, see, for example, J. Hoenes et al.: The Technology Behind Glucose Meters: Test Strips, Diabetes Technology & Therapeutics, Volume 10, Supplement 1, 2008, S-10 to S-26. Other types of test chemicals are possible and may be used to carry out the present invention.

[0031] As outlined above, the method involves capturing at least one image of at least a portion of a reagent test area to which a sample of bodily fluids has been applied, by using a camera. The term “capture at least one image” as used herein is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to one or more of, but are not limited to, imaging, image recording, image acquisition, and image capture. The term “capture at least one image” can include capturing a single image and / or multiple images, such as a series of images. For example, image capture can include sequentially recording a series of images, such as a video or moving image. Image capture can be initiated by a user action or can be initiated automatically, for example, when the presence of at least one object is automatically detected within the camera’s field of view and / or within a given sector of the field of view. These automatic image acquisition techniques are known, for example, in the field of automatic barcode readers, such as automatic barcode reading applications. Image acquisition can be performed, for example, by acquiring an image stream or "live stream" by a camera, and one or more of these images are stored and used as at least one first image or at least one second image, either automatically or through user interaction such as pressing a button. Image acquisition may be supported by the mobile device's processor, and image storage may occur within the mobile device's data storage device.

[0032] Acquiring at least one image may include applying a body fluid sample to a test strip and acquiring at least one image, and optionally, acquiring at least one image without applying the body fluid sample to the test strip, for example, before acquiring the image with the sample applied to the test strip. The latter image may be used specifically for comparison purposes and may be called a “blank image” or “dry image”. Sample application may generally be performed directly or indirectly, for example, via at least one capillary element. At least one image acquired after sample application may typically be called a “wet image,” even if the sample may be dry when the image is actually acquired. Wet images may typically be acquired after waiting at least a predetermined waiting time, e.g., 5 seconds or more, to allow the detection reaction to occur. Thus, for example, the method may include waiting at least a predetermined minimum amount of time between acquiring at least one arbitrary dry image and at least one wet image. This predetermined minimum amount of time may specifically be sufficient for the detection reaction to occur in the test strip. For example, the minimum amount of waiting time may be at least 5 seconds.

[0033] This method involves determining the concentration of an analyte, particularly the analyte concentration value, from the coloration of a test field. Therefore, this method can be an analytical measurement involving a change in at least one optical property of an optical test strip, which can be visually measured or determined by using a camera. Specifically, the analytical measurement can be, or include, a coloration reaction in the presence of at least one analyte to be determined. The term “coloration reaction” as used herein is a broad term and should be given its usual customary meaning to those skilled in the art, and should not be limited to any special or customized meaning. Specifically, the term can refer to a chemical, biological, or bodily reaction in which the color, specifically the reflectance, of at least one element involved in the reaction changes as the reaction progresses, but is not limited to this. The coloration can be detected by a mobile device, such as by a processor in the mobile device, and can be quantitatively evaluated by deriving at least one parameter from at least one image that quantifies or characterizes the coloration of the test field resulting from the presence and concentration of the analyte in the bodily fluid. For this purpose, one or more specific color coordinates can be used. Therefore, a mobile device, specifically the processor of a mobile device, can be configured to determine a change in color by determining one or more changes in color coordinates resulting from a detection response.

[0034] The concentration of at least one analyte, particularly the analyte concentration value, is determined from the color development of the test field. At least one image is used for this purpose. The analyte concentration value can serve as a numerical indicator of the results of the analytical measurement, for example, indicating the concentration of at least one analyte in a sample, such as blood glucose concentration.

[0035] The method may further include the step of displaying the analyte concentration value on the display of a mobile device or the like. Additionally or alternatively, the method may include storing at least one analyte concentration value in at least one data storage device of the mobile device. Again additionally and alternatively, the method may further include transmitting at least one analyte concentration value to another computer or the like, for example, for further evaluation, via at least one interface and / or at least one data transmission network.

[0036] Here, we will focus on the test strip fixing device of the present invention, which is configured for use in a method for determining the concentration of an analyte in a body fluid by using a mobile device equipped with a camera, and describe the structural elements of the test strip fixing device in more detail.

[0037] Therefore, in the first aspect, the present invention relates in particular to a test strip fixing device, The method is configured for use in a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, the method comprising capturing at least one image with the camera including at least a portion of an optical test strip and at least a portion of a test strip holder, wherein the optical test strip has a sample of body fluid applied to the reagent test area of ​​the optical test strip, the image includes at least a portion of the reagent test area to which the body fluid sample is applied, and the image includes at least a portion of the upper surface of the test strip holder. a) Essentially planar shape, b) Notch and, c) A top surface including a plurality of color reference fields having known reference color values, which include gray reference fields locally, particularly symmetrically, arranged around the notch and at least a portion of the non-gray reference field, and which are equipped with position detection code elements, d) A lower surface having fixing elements for a detachable connection of the optical test strip to the test strip fixing device, so that the reagent test area can be aligned with the notch, This relates to a test strip fixing device equipped with the following features.

[0038] The present invention provides a test strip fixing device that allows for the attachment and detachment of an optical test strip to the test strip fixing device, a color reference field positioned on the upper surface of the test strip fixing device, multiple color reference fields having known reference color values, and a notch that can be aligned with the reagent test area of ​​the optical test strip when the optical test strip is connected to the test strip fixing device. This allows for the precise positioning of (i) the optical test strip relative to the test strip fixing device, (ii) the optical test strip relative to the color reference field, and (iii) the reagent test area of ​​the optical test strip relative to the notch in a reproducible and efficient manner. All of these positioning aspects contribute to making a method for determining the concentration of an analyte in a body fluid more reliable, and the method uses a mobile device having a camera in addition to the optical test strip and test strip fixing device. In such a measurement method, for optimal performance of the method, for example with respect to the accuracy of the measurement results achieved, it is necessary to ensure the positioning of both the test strip and the color reference field relative to the camera and to each other. The latter aspect, namely the positioning of the test strip and the color reference field relative to each other, is particularly relevant when the measurement method includes not only reading color information from the test chemical, such as the reagent test field of the optical test strip, but also reading other information from the optical test strip, such as additional color information, calibration information, or lot-specific information. Such additional information may be provided, for example, on the carrier or support of the optical test strip.

[0039] Furthermore, the test strip fixing device of the present invention enables a reduction in the image processing power required, particularly for any pixel-based image processing capability, by defining and fixing the position of elements on the upper surface of the optical test strip and the reagent test field provided on the test strip (e.g., a color reference field). In particular, by combining this with the use of a position detection code element such as an ArUco code for the rapid and easy detection of the upper surface of the test strip fixing device in a (digital) image, all necessary elements can be identified with relatively low computational cost, i.e., in a resource-efficient manner.

[0040] The test strip fixing device has an essentially planar shape, such as a flat rectangular prism. Its upper surface may be provided in any geometric form or shape that provides a sufficiently large surface area to accommodate the notches, multiple color reference fields, and position detection code elements. Thus, any rectangular, trapezoidal, elliptical, or circular shape of the test strip fixing device or its upper surface may be appropriate. Typically, the test strip fixing device has four outer edges, two of which form a first pair of outer edges, and two of which form a second pair of outer edges. At least one of the pairs, specifically both outer edges of a pair, may be arranged essentially parallel to each other. Furthermore, the outer edges of the first pair may be longer than the outer edges of the second pair. In particular, the test strip fixing device has an essentially rectangular or trapezoidal shape, more specifically an essentially rectangular shape. Other shapes may also be used as appropriate.

[0041] Generally, the test strip fixing device has a height of 10 mm or less, specifically 5 mm or less, including the top surface, bottom surface, and fixing elements. Advantageously, the central region of the test strip fixing device, particularly with respect to the first and second pairs of outer edges, can provide the maximum height of the test strip fixing device. Additionally or alternatively, the bottom surface may be at least partially inclined toward the central region of the test strip fixing device toward at least one of the outer edges, specifically at least two of the outer edges, more specifically all of the outer edges, particularly with respect to the first and second pairs of outer edges. Advantageously, the central region of the test strip fixing device has a flat surface, specifically a flat surface essentially parallel to the top surface. In this regard, the term “essentially parallel” can refer to a parallel orientation and / or a deviation from a parallel orientation of >0° to 10°, particularly >0° to 5°. As an example, the central region of the test strip fixing device can provide the maximum height of the test strip fixing device, and the central region has a plane, specifically a plane essentially parallel to the top surface. The central area of ​​the test strip holder, which provides maximum height and / or has a flat surface, greatly simplifies the user's handling of the test strip holder, as the device can be stably placed on any flat surface, such as a table, and picked up more easily from there. This is particularly useful when handling the test strip holder requires picking up the device from such a flat surface for the purpose of performing analyte testing with test strips, such as blood glucose test strips.

[0042] Alternatively, the lower surface, particularly the plane of the central region of the test strip holder, may be offset from an orientation parallel to the upper surface such that the upper surface is inclined with respect to the lower surface (and therefore with respect to a horizontal support surface such as the surface of a table when the test strip holder is placed on a support surface) by an angle of, for example, 5° to 25° or 5° to 15°. In such a configuration, the region adjacent to the first outer edge of the outer edge of the test strip holder can provide the maximum height of the test strip holder. Furthermore, the region adjacent to one of the outer edges of the test strip holder located on the opposite side of the first outer edge can provide the minimum height of the test strip holder. Advantageously, in such a configuration, any influence of glare, particularly from ambient light and / or from a light source of the mobile device such as an LED, may be minimized or avoided due to the angle of the upper surface with respect to the camera of the mobile device, which in this case is predetermined at least to some extent.

[0043] The notches are typically positioned away from the outer edges of the test strip holder. Therefore, the notches may be positioned in the central region of the test strip holder, particularly with respect to the first and second pairs of outer edges. Additionally or alternatively, the notches may be positioned away from the geometric center of the test strip holder, specifically, away from the geometric center defined by the first and second pairs of outer edges. This allows the test strip to extend beyond the device or beyond its outer edges when inserted into the device, making it easier to grip the test strip and thus improving the user's handling of the test strip holder. Furthermore, any effects from lighting effects such as gloss can be minimized or avoided by appropriately positioning the notches within the test strip holder, as described in this paragraph.

[0044] Typically, at least some or all of the position-detecting code elements are positioned essentially on the outer edge of the test strip fixing device. Additionally or alternatively, at least some or all of the position-detecting code elements are positioned to define a color reference field on the top surface, specifically including a gray reference field.

[0045] Appropriate position detection code elements include any barcode and square marker. Additionally or alternatively, position detection code elements may include information specific to the test strip fixing device, which typically includes at least lot-specific information and / or calibration information regarding the color reference field. Particularly suitable position detection code elements include ArUco markers.

[0046] Furthermore, the upper surface of the test strip fixing device may include one or more check fields, for example, two, four, or six, each exhibiting at least one high-contrast edge, specifically at least one sharp high-contrast edge. In particular, each check field may include or consist of two or more distinct regions, at least one of which is white and at least one other which is black. Specifically, a check field may consist of at least one white region and at least one black region, for example, a rectangle, where the black and white regions are directly adjacent to each other. Thus, the black and white regions of the test field form edges, specifically sharp edges, at the transitions between them, i.e., the transitions from the black region to the white region. For example, four check fields can be provided, each having one white region and one black region, where the white and black regions are directly adjacent to each other within each check field. The test fields may be distributed symmetrically or randomly on the upper surface, for example, all or part of the test fields may be located near the outer edge of the test strip fixing device. Advantageously, in any given situation in which the measurement is performed (i.e., when an image is captured by the camera of a mobile device at a specific location with specific local illumination conditions), the check field facilitates the determination of the full range of detection from black to white. Furthermore, by providing a clearly defined, sharp transition edge from black to white, they also enable a reliable and efficient evaluation of the clarity of the captured image.

[0047] In embodiments, the gray reference field includes at least two, or at least three, different gray shades, e.g., three, four, five, or more different gray shades, more specifically three different gray shades. Different gray shades generally exclude pure white fields and pure black fields. However, the upper surface of the test strip fixing device may optionally further include one or more white and / or black reference fields in addition to the one or more check fields as described herein. Specifically, the gray reference field including at least two, or at least three different gray shades, is arranged locally, particularly essentially symmetrically, around the notches of the non-gray reference field and / or around at least some or all of them. More specifically, the gray reference field including at least two, or at least three different gray shades, is arranged locally, particularly essentially symmetrically, around the notches and around each of the non-gray reference fields. In this regard, the term “arranged locally” means that the gray reference fields are arranged in close proximity to the notches and / or non-gray reference fields, respectively. Advantageously, the gray base field is locally positioned around the notch and / or the non-gray base field such that at least two or at least three different gray shades are positioned around the notch and / or the non-gray base field at least two, at least three, or at least four times. In other words, in the latter position, the notch and / or at least part or all of the non-gray base field is surrounded by two, three, four or more redundant sets of gray base fields, each set containing at least two or at least three different gray shades. In particular, at least two, more specifically three or four of the redundant sets of gray base fields may be positioned around the notch and / or the non-gray base field.

[0048] In general, non-gray reference fields may be evenly distributed across the top surface of the test strip holder, particularly so that multiple color reference fields can be distributed essentially across the entire top surface. Non-gray reference fields may be distributed symmetrically or randomly across the top surface. When non-gray reference fields of the same color are used, for example, if a pair of two non-gray reference fields of the same color are present on the top surface, it is advantageous that each such pair of non-gray reference fields can be distributed asymmetrically across the top surface. In such an asymmetric distribution, for any particular lighting conditions, at least one of a given pair of non-gray reference fields can be considered for analytical measurement purposes, while the other of the pair of non-gray reference fields is more likely to be unused, for example, due to insufficient local lighting conditions at that particular location on the top surface of the test strip holder.

[0049] The fixing elements of a test strip fixing device generally include one or more guide elements for guiding the optical test strip while inserting it into the test strip fixing device. Suitable guide elements can be selected from a list including guide slots, guide notches, guide grooves, guide channels, guide tracks, engagement hooks, lugs, loops, recesses, cavities, depths, troughs, projections, openings, and orifices. Specifically, the fixing element includes at least two or at least three of the guide elements. More specifically, the fixing element includes at least two of the guide channels, orifices, and engagement hooks.

[0050] In some embodiments, the top surface of the test strip fixing device may include a protective frame. Specifically, such a protective frame may have a height of up to 0.5 mm or up to 1 mm and may enclose at least a portion of the top surface or the entire top surface of the test strip fixing device. Advantageously, the protective frame shields the top surface and elements on the top surface from, at least to some extent, any harmful impacts that may occur during handling of the test strip fixing device.

[0051] In particular, the upper and lower surfaces of the test strip fixing device, including the fixing elements and / or protective frame, may be formed as a single injection-molded part. The color reference field and / or position detection code elements can be applied to the upper surface by a printing process. Additionally or alternatively, the color reference field and / or position detection code elements may be printed on a label affixed to the upper surface. In the latter case of a label, providing a protective frame as described herein may be particularly beneficial.

[0052] In a further aspect of the present invention, a kit is provided comprising a test strip fixation device and an optical test strip. Thus, the test strip fixation device further comprises an optical test strip adapted to be detachably connected to the test strip fixation device. Typically, the optical test strip comprises a carrier and a reagent test area for applying a sample of body fluid. The reagent test area can be placed on a carrier. Advantageously, the carrier has a transparent zone or notched zone at the location of the reagent test area, so that when the test strip is connected to the test strip fixation device, the test field can be observed when viewed through the notch.

[0053] The notch of the test strip fixing device is typically larger than the reagent testing area. Specifically, the notch is larger than the reagent testing area of ​​the optical test strip. More specifically, the notch is sized to allow observation of at least a portion of the carriers of the optical test strip, particularly a portion of the carriers adjacent to the reagent testing area, when the optical test strip is connected to the fixing element of the test strip fixing device. Advantageously, the portion of the optical test strip carriers to be observed may include a white reference field and / or a black reference field. The white reference field may be provided by the white color of the carriers themselves.

[0054] The fixing element may be positioned essentially perpendicular to at least one of the outer edges of the test strip fixing device, particularly to at least one of the outer edges of a first or second pair of outer edges. More specifically, if the optical test strip is connected to the fixing element, the optical test strip extends at least 5 mm, for example at least 8 mm, particularly at least 10 mm, beyond one of the outer edges.

[0055] In a further embodiment, as generally described herein, the present invention relates to a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, an optical test strip, and a test strip fixing device as described herein, (i) To provide an optical test strip, wherein the optical test strip comprises a carrier and a reagent test area disposed on the carrier, and the carrier has a transparent zone or a notched zone at the location of the reagent test area. (ii) Specifically, the optical test strip is detachably connected to the test strip fixing device such that the sample application area of ​​the reagent test region faces away from the lower surface of the test strip fixing device, (iii) Applying a sample of body fluid to the reagent test area, particularly from the underside of the test strip fixing device, so that a color is formed in the reagent test area, and that the color can be observed from above through the notch of the test strip fixing device and through the transparent zone of the carrier of the optical test strip or through the notch zone. (iv) capturing at least one image by camera that includes at least a portion of the optical test strip and at least a portion of the upper surface of the test strip fixing device, wherein the image includes at least a portion of the reagent test area to which the body fluid sample is applied, and the image further includes at least a portion of a color reference field that includes at least a portion of the gray reference field, (v) Determining the concentration of the analyte from the color formed in the reagent test area when a sample of body fluid is applied, taking into consideration at least a portion of the color reference field, which includes the gray reference field, This includes methods.

[0056] In the embodiment, at least one image captured in step (iv) may include all of the color reference fields, and more specifically, all of the gray reference fields.

[0057] Advantageously, determining the concentration of the analyte in step (v) further includes considering local intensity variations in at least one image captured in step (iv). Such local intensity variations may occur at one or more locations in the color reference field, for example, due to non-uniform lighting conditions. A gray reference field can be used to account for local intensity variations at one or more locations in the color reference field. For this purpose, as described herein, the gray reference field is particularly useful when it is locally positioned around the notch and / or around the non-gray color reference field, and at least two or at least three different gray shades are positioned at least two, at least three, or at least four times around the notch and / or the non-gray color reference field.

[0058] In general, the method for determining the concentration of an analyte in a bodily fluid according to the present invention involves using a mobile device having a camera and a processor. The method includes, for example, the above steps which can be performed in a given order. However, it should be noted that a different order may be possible for at least some of the steps. Furthermore, it is possible to perform one or more method steps once or repeatedly. Furthermore, it is possible to perform two or more method steps simultaneously or in overlapping order. The method may include further method steps not described.

[0059] In another aspect of the present invention, a computer program is provided which, when the program is executed by a mobile device as described herein, includes instructions causing the mobile device to perform at least steps iv) and v) of the method described herein.

[0060] In another aspect of the present invention, a computer-readable storage medium is provided, which, when executed by the mobile device described herein, provides instructions causing the mobile device to perform at least steps iv) and v) of the method described herein.

[0061] Further optional features and embodiments are disclosed in more detail in subsequent descriptions of embodiments, preferably in conjunction with dependent claims. Here, each optional feature may be implemented independently and in any viable combination, as will be understood by those skilled in the art. The scope of the present invention is not limited by preferred embodiments. Embodiments are schematically shown in the figures, where the same reference numerals in these figures refer to identical or functionally equivalent elements. [Brief explanation of the drawing]

[0062] The diagram is as follows: [Figure 1] A schematic diagram of the underside of an exemplary embodiment of a test strip fixing device is shown. [Figure 2] Figure 1 shows a schematic side view of an embodiment of the test strip fixing device. [Figure 3] This shows a schematic top view of an exemplary embodiment of a test strip fixing device. [Figure 4] A schematic perspective view shows an embodiment of a mobile device, as well as a kit comprising a test strip fixing device and an optical test strip. [Figure 5] A flowchart illustrating an embodiment of a method for determining the concentration of at least one analyte in a body fluid is shown. [Modes for carrying out the invention]

[0063] Figures 1 and 2 show exemplary embodiments of a test strip fixing device. Figure 1 shows the bottom surface (104) of the test strip fixing device of this embodiment, and Figure 2 provides a side view thereof. Overall, the test strip fixing device has an essentially planar shape such that the height of the test strip fixing device is much smaller than the length and width of its bottom surface (104) and its top surface (110). In particular, the test strip fixing device has a rectangular shape limited by its outer edges (108) and its corners (124), with two of the outer edges (108) forming a first pair of outer edges, and the other two of the outer edges (108) forming a second pair of outer edges, with each pair of outer edges (108) arranged parallel to each other.

[0064] Generally, a test strip fixing device can have a height of 10 mm or less, including a top surface (110), a bottom surface (104), and fixing elements. In the illustrated embodiment, the central region (160) of the bottom surface of the test strip fixing device provides the maximum height of the test strip fixing device. Furthermore, the bottom surface (104) may be at least partially inclined toward the central region (160) of the bottom surface of the test strip fixing device from at least one of the outer edges (108), for example, two, three, or four of the outer edges (108). In this embodiment, the bottom surface (104) is at least partially inclined toward the central region (116) of the test strip fixing device from all four of the outer edges (108), as shown in Figures 1 and 2 by lines indicating the inclined portion (104a) of the bottom surface (104). In particular, the central region (160) has a plane that is essentially parallel to the top surface (110) of the test strip fixing device. As will be readily apparent to those skilled in the art, the inclined portion (104a) of the lower surface (104) can be designed in the form of a continuously inclined region, that is, without the small steps (104a) shown in Figures 1 and 2, respectively.

[0065] Referring again to Figures 1 and 2, respectively, a notch (116) is provided, located away from the outer edge (108) of the test strip fixing device. Furthermore, the notch (116) is located in the central region of the test strip fixing device with respect to the first and second pairs of outer edges (108), particularly in the central region that at least partially overlaps with the central region (160). Moreover, in this embodiment, the notch (116) is located away from the geometric center defined by the first and second pairs of outer edges of the test strip fixing device. In other words, if two straight lines are drawn from each of the two corners (124) of the lower surface (104) of the test strip fixing device, and the two corners (124) are diagonally opposite each other, the intersection of these two straight lines represents the aforementioned geometric center. The notch (116) is located away from the geometric center.

[0066] In the embodiments shown in Figures 1 and 2, respectively, the notch (116) has a circular shape. Furthermore, the notch (116) is provided with a chamfered portion (116a). As a result, the area of ​​the notch (116) located on the upper surface (110) of the test strip fixing device is expanded to some extent toward the lower surface. The cavity thus formed has the notch (116) at the center of the cavity and facilitates the precise application of a body fluid sample to the reagent test field of the optical test strip used with the test strip fixing device.

[0067] The lower surface (104) is provided with a fixing element for detachably connecting an optical test strip (not shown in Figures 1 and 2) to a test strip fixing device. In this embodiment, the fixing element is positioned perpendicular to one of a pair of outer edges. In this configuration, the optical test strip is connected to the test strip fixing device by inserting the optical test strip in the direction indicated by arrow A in Figure 1.

[0068] The fixing element may comprise one or more guide elements (170, 172, 174). In the illustrated embodiment, the fixing element comprises at least three guide elements, specifically a guide channel (170), an orifice (172), and an engagement hook (174). The guide elements (170, 172, 174) together ensure proper positioning of the optical test strip (118) relative to the test strip fixing device. In particular, the guide channel (170) is essentially U-shaped and functions to accommodate the optical test strip (118) when connected to the test strip fixing device, and is configured to guide the optical test strip (118) while inserting the test strip into the guide channel (170). The orifice (172) through which the optical test strip (118) is pushed while inserting the test strip into the guide channel (170) is configured to hold the test strip in place, in particular when the test strip fixing device is inverted or otherwise rotated. Furthermore, the engaging hook (174) is configured to securely fasten the optical test strip (118) to the test strip fixing device as soon as the corresponding holes in the optical test strip (118) are aligned with the engaging hook (174), so that the test strip can be locked in place.

[0069] An optical test strip (118) used with a test strip fixation device is adapted to be detachably connected to the test strip fixation device. Such an optical test strip (118) typically includes a carrier and a reagent test area (120) for applying a body fluid sample. The reagent test area (120) may be positioned on the carrier. Specifically, the carrier may have a transparent zone or a notched zone at the location of the reagent test area (120).

[0070] In this specification, when an optical test strip (118), such as those described above, is connected to a test strip fixing device, the optical test strip (118) typically extends at least 5 mm beyond one of its outer edges (108), for example, beyond the lower of the outer edges (108) as shown in Figure 1. This ensures robust and convenient user operation of the test strip fixing device and the optical test strip.

[0071] Furthermore, when the optical test strip (118) is connected to the test strip fixing device, the reagent test area (120) of the optical test strip (118) can be aligned with the notch (116) of the test strip fixing device. Generally, the notch (116) of the test strip fixing device is larger than or equal to the size of the reagent test area (120) of the optical test strip (118) used with the test strip fixing device. Specifically, the notch (116) is sized to allow observation of at least a portion of the carriers of the optical test strip (118), for example, a portion of the carriers adjacent to the reagent test area (120), when the optical test strip (118) is connected to the fixing elements (170, 172, 174) of the test strip fixing device.

[0072] Referring to Figure 3, the test strip fixing device comprises a top surface (110) having a plurality of color reference fields (112, 114, 148, 150, 152, 154) having known reference color values. The color reference fields include gray reference fields (114, 150) positioned locally and, in this embodiment, symmetrically around the notch (116) and around the non-gray reference fields (112, 148, 152, 154).

[0073] In general, the color-based fields (112, 114, 148, 150, 152, 154) can be equally distributed on the top surface (110), in particular, so that multiple color-based fields (112, 114, 148, 150, 152, 154) can be distributed across the entire top surface (110). For example, the color-based fields (112, 114, 148, 150, 152, 154) may be arranged in a matrix pattern, such as a rectangular matrix pattern. However, the color-based fields (112, 114, 148, 150, 152, 154) may also be arranged in other ways, such as separately from one another. In the illustrated embodiment, the top surface (110) includes multiple gray-based fields (112, 148, 152, 154) surrounding a non-gray-based field (114, 150). Non-gray-based fields (112, 148, 152, 154) and gray-based fields (114, 150) do not need to overlap.

[0074] In Figure 3, the gray reference field (114, 150) contains three or more different shades of gray. Specifically, the gray reference field (114, 150) containing different shades of gray is locally positioned around the notch. Furthermore, the gray reference field (114, 150) containing different shades of gray is locally positioned around at least some of the non-gray reference fields (112, 148, 152, 154).

[0075] Furthermore, the top surface (110) is provided with a position detection code element (122). In this embodiment, the position detection code element (122) is essentially located on the outer edge (108) of the test strip fixing device. In addition, as an alternative to the illustrated embodiment, the position detection code element (122) may be located on the top surface (110) to demarcate the color reference fields (114, 150), particularly the gray reference fields (112, 114, 148, 150, 152, 154).

[0076] The position detection code element (122) may be at least one of the following position markers, such as an ArUco code, barcode, QR code (registered trademark), label, or a combination thereof, or may include one. Specifically, the position detection code element (122) may include one or more ArUco codes, for example, at the corners of a rectangular matrix containing color-referenced fields (112, 114, 148, 150, 152, 154). In general, the position detection code element (122) may be located at at least one corner (124) of the top surface (110). For example, at least one position detection code element (122) may be located at each of the corners (124) of the top surface (110), specifically, so that the position detection code element (122) is visible together with multiple color-referenced fields (112, 114, 148, 150, 152, 154).

[0077] The position detection code element (122) used herein includes a square marker, in particular an ArUco marker. Furthermore, the position detection code element (122) may also include information specific to the test strip fixing device, which may include, for example, lot-specific information and / or calibration information regarding the color reference fields (112, 114, 148, 150, 152, 154). In addition, the position detection code element (122) may include information regarding the orientation of the top surface (110) of the test strip fixing device.

[0078] The top (110) and bottom (104) including the fixed elements can be efficiently formed as a single injection-molded part. The color reference fields (112, 114, 148, 150, 152, 154) and position detection code elements (122) may be applied to the top (110) by a printing process. Alternatively, the color reference fields (112, 114, 148, 150, 152, 154) and position detection code elements (122) may be printed on a label attached to the top surface, for example, by using adhesive, adhesive tape, etc. In an exemplary embodiment, the color reference fields (114, 150) including the gray color reference field (112, 114, 148, 150, 152, 154) may be printed on a pre-printed gray background on the top (110). Therefore, the color reference fields (112, 114, 148, 150, 152, 154) may overlap with the gray-colored background of the top surface (110).

[0079] In Figures 3 and 4, the top surface (110) includes a rectangular notch (116). Therefore, as in the cases of Figures 3 and 4, when the optical test strip (118) is connected to the test strip fixing device, the optical test strip (118) or at least a portion of it can be seen through the notch (116). Specifically, the reagent test area (120) of the optical test strip (118) can be seen through the notch (116).

[0080] Figure 4 is a perspective view of an exemplary embodiment of a kit comprising a mobile device and a test strip fixing device and an optical test strip used therewith. The kit comprises at least one test strip fixing device and at least one optical test strip (118). Furthermore, the kit may comprise at least one mobile device (128). The mobile device (128) may be at least one of the following: a mobile phone, a smartphone, a tablet computer, etc. Furthermore, the mobile device (128) has at least one camera (130). The camera (130) of the mobile device (128) may be configured to record images (also referred to herein as “captured images”), specifically color images. Thus, the camera (130) may be a color camera and may comprise at least three color sensors, such as at least one color sensor for R, G, and B colors.

[0081] Furthermore, the mobile device (128) generally includes at least one processor (132). The processor (132) can be configured, specifically by software programming, to perform one or more method steps of the method for determining the concentration of an analyte in a bodily fluid according to the present invention. An exemplary embodiment of the method is shown in Figure 5 and will be described in further detail below.

[0082] The processor (132) may be configured to support the acquisition of images of at least one of the top surfaces (110) of the test strip fixing device. Specifically, the processor (132) may prompt the user of the mobile device (128) to acquire an image. Additionally or alternatively, the processor (132) may be configured to automatically acquire an image of the top surface (110), particularly when the top surface (110) is within the field of view.

[0083] The top surface (110) can be specifically embodied in any one of the embodiments disclosed in relation to Figure 3, as described in more detail above. The top surface (110) comprises a plurality of color reference fields (112, 114, 148, 150, 152, 154) having known reference color values. Furthermore, the test strip fixing device comprises at least one notch (116). Thus, the optical test strip (118) can be visible through the notch (116), in particular when the optical test strip (118) is connected to the test strip fixing device, so that both the top surface (110) and the optical test strip (118) can be visible on at least one image captured by the camera (130) of the mobile device (128). Specifically, at least one reagent test area (120) of the optical test strip (118) may be visible through a notch (116), more specifically when viewed from the top (110) direction. In such a configuration, a body fluid sample is applied to the reagent test area (120) of the optical test strip (118) from the bottom direction. The color formed in the reagent test area (120) is then visible through the notch (116). Additionally or alternatively, a body fluid sample may be applied to the optical test strip before being connected to the test strip fixation device. Furthermore, additionally or alternatively, an optical test strip having a capillary for receiving a body fluid sample and / or transferring a body fluid sample to the reagent test area (120) may be used with the test strip fixation device.

[0084] The top surface (110) further has at least one position-detecting code element (122). The position-detecting code element (122) is positioned on the top surface (110) such that it may be detectable by the camera (130) of the mobile device (128). At least one position-detecting code element (122) can be used to identify the orientation of the test strip fixing device and its top surface (110) relative to the camera of the mobile device. Specifically, the processor (132) of the mobile device (128) may be configured to detect the position-detecting code element (122) in the image captured by the camera (130) and to obtain further information regarding the orientation of the top surface (110).

[0085] Figure 5 shows a flowchart of an exemplary embodiment of a method for determining the concentration of at least one analyte in a body fluid. The method includes using at least one mobile device (128) having at least one camera (130). The method further includes using at least one optical test strip (118) and the test strip fixing device described herein.

[0086] This method specifically includes the following steps, which can be performed in a given order. Furthermore, different orders are also possible. Two or more method steps may be performed entirely or partially simultaneously. Furthermore, one, two or more, or all method steps may be performed once or repeatedly. This method may include additional method steps not described.

[0087] This method, (i) To provide an optical test strip (118) (indicated by reference numeral 210), wherein the optical test strip (118) comprises a carrier and a reagent test area (120) disposed on the carrier, and the carrier includes a notched zone (or transparent zone) at the location of the reagent test area (120), (ii) Specifically, (indicated by reference numeral 220) the optical test strip (118) is detachably connected to the test strip fixing device such that the sample application area of ​​the reagent test area (118) faces away from the lower surface (104) of the test strip fixing device, (iii) Applying a sample of a body fluid (indicated by reference numeral 230) to the reagent test area (120), thereby forming a color on the reagent test area (120), which can be observed from the top surface (110) through the notch (116) of the test strip fixing device and through the notched zone (or transparent zone) of the carrier of the optical test strip (118), (iv) Taking at least one image by camera (130) including at least a portion of the optical test strip (118) (indicated by reference numeral 240) and at least a portion of the upper surface (110) of the test strip fixing device, wherein the image includes at least a portion of the reagent test area (120) on which the body fluid sample is applied, and the image further includes at least a portion of a color reference field including at least a portion of the gray reference field, (v) Determining the concentration of the analyte from the color formed in the reagent test area (120) when a sample of body fluid is applied, taking into consideration at least a portion of the color reference field including the gray reference field (indicated by reference numeral 250), Includes.

[0088] In step (iv), imaging of the reagent test area (120) may be performed by the processor (132), for example, by prompting the user to take an image and / or by automatically taking an image.

[0089] Furthermore, the method may include analytical measurements comprising detecting the color value of a reagent test area (120) to which a sample of body fluid has been applied, and determining the analyte concentration based on the color reaction of the reagent test area (120). For this purpose, the method may further include determining measured reference color values ​​from an image for at least some of the color reference fields (112, 114, 148, 150, 152, 154), and determining the relationship between at least some of the measured reference color values ​​and the corresponding known reference color values. The determined relationship can then be used to correct the measured color values ​​of the color reaction, in particular by using a color transformation matrix. The analyte concentration can then be determined using the corrected color values.

[0090] A method for determining the concentration of an analyte in a body fluid, specifically steps (iv) and (v) of this method, may be at least partially computer-implemented. The mobile device (128) can be configured, specifically, to execute a computer program, when performed by the mobile device (128), which causes the processor (132) of the mobile device (128) to perform steps (iv) and (v) of this method. The processor (132) can be configured, specifically, to capture at least one image of the reagent test area (120), for example, by prompting the user to capture at least one image and / or by automatically capturing at least one image.

[0091] Furthermore, the processor (132) may be configured, specifically by software programming, to determine the analyte concentration based on the color reaction of the reagent test area (120). The processor (132) may be configured to evaluate the captured image, derive one or more changes in color coordinates that occur during the color reaction, or any linear or nonlinear combination thereof, and determine the analyte concentration by converting at least one change in color coordinates into an analyte concentration value. Specifically, the processor (132) may be configured to use a relationship between at least a portion of the measured reference color values ​​and corresponding known reference color values ​​in order to derive true color values ​​from the captured image. Thus, the processor (132) can correct the measured color values ​​of the captured image by converting the measured color values ​​into true color values ​​using a color conversion matrix determined from the relationship described herein.

[0092] Specifically, determining the concentration of the analyte in step (v) may further include considering local intensity variations in at least one image captured in step (iv), where the local intensity variations may occur at one or more locations in the color reference field, and the gray reference field is used to consider the local intensity variations. [Explanation of symbols]

[0093] 104 Bottom surface 104a Sloping portion on the bottom surface 108 Outer edge 110 Top 112 color reference fields 114 Gray base field 116 Notch 116a Chamfered portion of the notch 118 Optical test strips 120 Reagent Testing Area 122 Location detection code elements 124 angle 126 Kit 128 Mobile devices 130 Cameras 132 processors 148 color reference field (black) 150 gray base field 152 color reference field (white) 154 color reference field 160 Central area of ​​the lower surface 170 Guidance Channel 172 Orifice 174 Engaging Hook We offer 210 optical test strips. 220 Removably connect the optical test strip to the test strip fixing device. 230 Apply the body fluid sample to the reagent test area. 240. A camera captures an image including a portion of the optical test strip and a portion of the top surface of the test strip fixing device. 250 Determine the concentration of the analyte.

Claims

1. A test strip fixing device, The method is configured for use in a method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, wherein the method includes capturing at least one image with the camera that includes at least a portion of an optical test strip and at least a portion of the test strip fixing device, wherein the optical test strip has a sample of the body fluid applied to the reagent test area of ​​the optical test strip, the image includes at least a portion of the reagent test area to which the sample of the body fluid is applied, and the image includes at least a portion of the upper surface of the test strip fixing device. a) an essentially planar shape having a rectangular shape limited by its outer edge and its corners, b) Notch and, c) A top surface including a plurality of color reference fields having known reference color values, which include gray reference fields locally positioned around the notch and around at least a portion of the non-gray reference field, and which are equipped with position detection code elements, d) A lower surface having fixing elements for a detachable connection of the optical test strip to the test strip fixing device, such that the reagent test area can be aligned with the notch, Equipped with, The lower surface is at least partially inclined toward the central region of the test strip fixing device from at least one of its outer edges, The plane of the central region of the test strip fixing device is offset by an angle of 5° to 25° from the orientation parallel to the upper surface. A test strip fixing device in which the notch is located away from the outer edge of the test strip fixing device, and / or the notch is located in the central region of the test strip fixing device with respect to the first and second pairs of outer edges, and / or the notch is located away from the geometric center defined by the first and second pairs of outer edges of the test strip fixing device.

2. The test strip fixing device according to claim 1, wherein the test strip fixing device has a height of 10 mm or less including the upper surface, the lower surface, and the fixing element.

3. The test strip fixing device according to claim 1 or 2, wherein the test strip fixing device comprises four outer edges, two of which form a first pair of outer edges, and two of which form a second pair of outer edges, and at least one of the pairs of outer edges is arranged substantially parallel to each other, and the outer edges of the first pair are longer than the outer edges of the second pair.

4. The test strip fixing device according to any one of claims 1 to 3, wherein at least a portion of the position detection code elements are essentially located on the outer edge of the test strip fixing device, and / or at least a portion of the position detection code elements are positioned to include the gray reference field so as to define the color reference field on the upper surface.

5. The test strip fixing device according to any one of claims 1 to 4, wherein the position detection code element includes a barcode and a square marker, and / or the position detection code element includes information specific to the test strip fixing device, wherein the information includes at least lot-specific information and / or calibration information relating to the color reference field.

6. The test strip fixing device according to any one of claims 1 to 5, wherein the gray reference field comprises at least two or at least three different gray shades, and the gray reference field comprising at least two or at least three different gray shades is locally positioned around the notch and / or around at least some of the non-gray reference fields.

7. The test strip fixing device according to any one of claims 1 to 6, wherein the fixing element comprises one or more guide elements.

8. The test strip fixing device according to any one of claims 1 to 7, wherein the upper surface and the lower surface including the fixing element are formed as a single injection-molded part, and the color reference field and the position detection code element are applied to the upper surface by a printing process, or the color reference field and the position detection code element are printed on a label applied to the upper surface.

9. A kit comprising an optical test strip fitted to be detachably connected to the test strip fixing device, wherein the optical test strip comprises a carrier and a reagent test area for applying the sample of a body fluid, the reagent test area being positioned on the carrier and the carrier having a transparent zone or a cutout zone at the location of the reagent test area.

10. The kit according to claim 9, wherein the notch of the test strip fixing device has a size greater than or equal to the reagent test area.

11. The test strip fixing device according to claim 9 or 10, wherein the fixing element is positioned substantially perpendicular to at least one of a first or second pair of outer edges, specifically, when the optical test strip is connected to the fixing element, the optical test strip extends at least 5 mm beyond one of the outer edges.

12. A method for determining the concentration of an analyte in a body fluid by using a mobile device having a camera, an optical test strip, and a test strip fixing device according to any one of claims 1 to 11, (i) To provide the optical test strip, wherein the optical test strip comprises a carrier and a reagent test area disposed on the carrier, and the carrier has a transparent zone or a notched zone at the location of the reagent test area, (ii) Specifically, the optical test strip is detachably connected to the test strip fixing device such that the sample application area of ​​the reagent test region is positioned away from the lower surface of the test strip fixing device, (iii) Applying the sample of the bodily fluid to the reagent test area, thereby forming a color in the reagent test area, the color being observable from above through the notch of the test strip fixing device, and through the transparent zone of the carrier of the optical test strip, or through the notch zone, (iv) capturing with the camera at least one image including at least a portion of the optical test strip and at least a portion of the upper surface of the test strip fixing device, wherein the image includes at least a portion of the reagent test area to which the sample of the body fluid is applied, and the image further includes at least a portion of the color reference field including at least a portion of the gray reference field, (v) Determining the concentration of the analyte from the color formed in the reagent test area when the sample of the body fluid is applied, taking into consideration at least a portion of the color reference field including the gray reference field, Methods that include...

13. The method according to claim 12, wherein determining the concentration of the analyte in step (v) further includes considering local intensity variations in the at least one image captured in step (iv), the local intensity variations may occur at one or more locations in the color reference field, and the gray reference field is used to consider the local intensity variations.

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